CLIMATE AND CLIMATE CHANGE MIDTERM EXAM ATM S 211 FEB 9TH 2012 V1

Transcription

1 CLIMATE AND CLIMATE CHANGE MIDTERM EXAM ATM S 211 FEB 9TH 2012 V1 Name: Student ID: Please answer the following questions on your Scantron Multiple Choice [1 point each] (1) The gases that contribute to the greenhouse effect on Earth are, in order of greatest to smallest in importance, (a) CO2, H20, CH4 (b) H20, CO2, CH4 (c) CH4, CO2, H20 (d) H20, CH4, CO2 (2) What is geostrophic balance? (a) The exact balance of incoming SW and outgoing LW radiation at the top of the atmosphere. (b) The exact balance of vertical pressure gradient and gravity in the atmosphere. (c) The exact balance of the Coriolis force, horizontal pressure gradient force and friction. (d) The exact balance of the Coriolis force and the horizontal pressure gradient force. (3) The order of the atmospheric layers, starting from closest to the surface to the top of the atmosphere, is (a) Mesosphere, Troposphere, Thermosphere, Stratosphere (b) Troposphere, Stratosphere, Mesosphere, Thermosphere (c) Thermosphere, Mesophere, Troposphere, Stratosphere (d) Troposphere, Mesosphere, Stratosphere, Thermosphere 1

2 2 ATM S 211 FEB 9TH 2012 V1 (4) What physical law gives the flux of energy of an idealized object above 0 K? (a) P = ρrt (b) S o (r/r 0 ) 2 (c) σt 4 (d) hν (5) How much would the sea level rise if all of the Arctic sea ice melted? (a) 0 m (b) 5 m (c) 10 m (d) 50 m (6) When did the Earth form? (a) 10 billion years ago (b) 4.6 billion years ago (c) 446 million years ago (d) 6,000 years ago (7) Given light of wavelength λ a = 600nm and light of λ b = 550nm, which has a higher energy per photon? (a) E a > E b (b) E a = E b (c) Neither has energy because light at these wavelengths carries no energy (d) E b > E a (8) On average, how do high clouds affect the surface temperature (compared to a clear sky)? (a) High clouds warm the surface by increasing the greenhouse effect (b) High clouds cool the surface by increasing the energy emitted to space (c) High clouds cool the surface by increasing the albedo (d) It depends on whether they are comprised of ice or liquid water (9) For winds that last six hours or more, such as a midlatitude storm, the air movement is modified by which causes the air to be deflected to. (a) Hydrostatic Force; the right in the Northern Hemisphere (b) Coriolis Force; the right in the Northern Hemisphere (c) Friction; the left in the Northern Hemisphere (d) Coriolis Force; the left in the Northern Hemisphere

3 Student ID: CLIMATE AND CLIMATE CHANGE MIDTERM EXAM 3 (10) On average, how do low clouds affect the surface temperature (compared to a clear sky)? (a) Low clouds warm the surface by increasing the greenhouse effect (b) Low clouds cool the surface by increasing the energy emitted to space (c) Low clouds cool the surface by increasing the albedo (d) It depends on whether they are comprised of ice or liquid water (11) Increasing carbon dioxide will cause sea ice to reduce in spatial coverage. In turn, the reduced sea ice extent is a (a) Positive feedback on surface temperature because it has a greater albedo than ocean (b) Positive feedback on surface temperature because it has a lower albedo than ocean (c) Positive feedback on surface temperature because sea ice has lower heat capacity than ocean (d) Both B and C are true (12) Air over the oceans is colder in summer and warmer in winter compared with air over the continental regions. This is because (a) Water is translucent and has a relatively high heat capacity compared to dirt (b) Compared to dirt, a thicker layer of water participates in the seasonal cycle (c) The albedo of water is greater than that of land and thus reflects more solar radiation (d) Both A and B are true (e) The effect is due to the changes in circulation between continents and oceans (13) This early atmosphere was rich in CO 2 and H 2 O. How did oxygen enter our atmosphere? (a) Meteorites. (b) From organisms that evolved to convert CO2 and H20 into sugars (energy), resulting in the waste product oxygen. (c) Volcanic emissions. (d) Methanogenic bacteria. (14) In the sea breeze, which onsets quickly (< 3 hours), air tends to move. (a) From areas of high pressure to low pressure (b) From areas of low pressure to high pressure (c) Along lines of equal pressure (isobars) (d) Across lines of equal pressure (isobars)

4 4 ATM S 211 FEB 9TH 2012 V1 (15) The net effect of circulation is to move warm air from the and thus moderate the equator-to-pole energy gradient created by. (a) the tropics to the poles; the difference insolation absorbed in day and night (b) the tropics to the poles; ocean circulation (c) from the surface up to the tropopause; more heating near the ground than aloft (d) the tropics to the poles; the latitudinal distribution of absorbed insolation (e) from the surface up to the tropopause; more heating in the atmosphere than at the surface from GHGs (16) After the sun rises, rapid heating of the air over the land compared to that over the ocean often causes of near surface air over the land. (a) Localized subsidence and high pressure. (b) Localized convection and high pressure. (c) Localized subsidence and low pressure. (d) Localized convection and low pressure. (17) The first step in the generation of a sea breeze is. (a) air over land expands and builds a pressure gradient at the surface that pushes air offshore (b) air over land expands and builds a pressure gradient at the surface that pushes air onshore (c) hot air over land rises, cools and forms a cloud (d) air over land expands and builds a pressure gradient aloft that pushes air offshore (18) At a constant pressure, hot air than cold air (a) is more dense (b) is less dense (c) has more vapor (d) has less vapor (19) Let s say we are flying over a large, flat part of Africa. Half of the area is hotter than the other half. The surface pressure is 1000 hpa everywhere. If we fly over at an elevation of 500 m above the surface, in which area does the pressure gauge (altimeter) in our plane read the lowest pressure? (a) The cold part. (b) The hot part. (c) The gauge reads the same pressure everywhere. (d) The gauge varies with the latitude and the temperature of the surface.

5 Student ID: CLIMATE AND CLIMATE CHANGE MIDTERM EXAM 5 (20) What is the relationship of absorbed solar to outgoing infrared in the tropics? (a) Absorbed Solar > emitted IR (b) Absorbed Solar < emitted IR (c) Absorbed Solar = emitted IR (d) It varies throughout the year. (21) What is the relationship of absorbed solar to outgoing infrared at the poles? (a) Absorbed Solar > emitted IR (b) Absorbed Solar <emitted IR (c) Absorbed Solar = emitted IR (d) This varies depending on time of year. (22) What place experiences the greatest seasonal variability in temperature? (a) The North Atlantic Ocean (b) Central Canada (c) Costa Rica, Central America (d) Mumbai, India. (23) If Earth had no greenhouse gases, the planet would be? (a) Too hot to support life. (b) Cooler but still able to support life. (c) Too cold to support life. EDIT: COMPLEX LIFE (d) It depends on the species of aerosol in the GHG-free atmosphere. (24) How was the atmosphere on Earth first formed? (a) Spontaneous combustion. (b) By comets and meteors, which were much more common at that time, delivering volatiles. (c) Evaporation from the ocean. (d) Volcanic emissions. (25) Has there been a steady decrease in the height of Greenland in the 20th Century? (a) Yes. (b) No. (c) The height has increased and decreased due to changing wind patterns. (d) Yes, because of dramatic increases in the calving rate of glacial ice into the surrounding ocean.

6 6 ATM S 211 FEB 9TH 2012 V1 (26) Recall homework 2 in which we calculated emissivity for a single layer atmosphere. If the atmosphere were to suddenly become a perfect emitter (i.e., if e = 1 rather than e = 0.8), what would happen to the surface temperature? (a) The surface temperature would be lower. (b) The surface temperature would be the same. (c) The surface temperature would be higher. (d) There would be initial warming followed by cooling as the planet moves toward radiative equilibrium. (27) In the stratosphere, why does temperature increase with increasing height? (a) Conduction. (b) Convection. (c) Greater absorption of ultraviolet radiation at the top of the stratosphere. (d) The pressure and density rapidly decrease as you go up through the stratosphere, thus the ideal gas law requires temperature to increase too. (28) Consider the diurnal (daily) cycle of temperature at the surface. Why is the temperature maximum in the mid-to-late afternoon? (a) There is a net energy gain at the surface from dawn to midafternoon. (b) Clouds form in mid-to-late afternoon, cutting down the solar heating and cooling the surface. (c) The intensity of solar radiation is at a maximum at this time. (d) Late in the day, evaporation from the surface increases and this cools the surface. (29) Why are there winds? (a) Because air flows down-hill. (b) Because of temperature differences. (c) Because air flows from high density to low density. (d) Because air flows along isobars. (30) Why are there jets in the midlatitudes in the upper troposphere? (a) Air is warmer in the tropics than the poles, resulting in a poleward pressure gradient that increases with increasing height. (b) Because air near the surface experiences the drag of surface friction, while air in the upper troposphere does not. (c) Due to variations in temperature between continents and ocean. (d) Due to the constant bending by the Coriolis force. (e) Both A and D are correct.

7 Student ID: CLIMATE AND CLIMATE CHANGE MIDTERM EXAM 7 (31) What would happen if gravity suddenly doubled on Earth, but the mass of the atmosphere did not change? (a) Surface pressure would stay the same but the density would increase. (b) Surface pressure would increase but the density would stay the same. (c) Surface pressure and density would both increase. (d) Surface density and pressure would stay the same because the atmosphere is in hydrostatic balance. Short Answer [3 points] Please answer this below or on the back of the page. We expect at most a half page. A diagram may be helpful, but isn t necessary to answer the problem correctly. [If you do draw a diagram, be sure to label and axes, arrows, etc.] (1) Describe the Greenhouse Effect and how it affects the temperature and radiation emitted at the surface, in the atmosphere, and at top of the atmosphere.